APPARATUS FOR DETECTING OBJECT INFORMATION BY OPTICAL SCAN

摘要

PROBLEM TO BE SOLVED: To prevent detection of wrong object information due to a scan angle and noises. SOLUTION: The light from a light-emitting element 16 is reflected by a rotatable scan mirror and radiated to a retroreflection body 12. The light reflected by the retroreflection body 12 is detected by a photodetecting element 17 after being reflected at the scan mirror. An energy of the detected light is compared with a threshold value at a comparator 27, thereby detecting information on an object 24a, 24b in an optical scan range according to this apparatus. A threshold value variable means 30 is set in the apparatus for changing the threshold value in accordance with the energy of the detected light at the photodetecting element 17. The threshold value variable means 30 is constituted of a voltage division circuit 32 and an integration circuit 34. Even when the detected energy of the photodetecting element 17 differs because of a scan angle or is raised by a fixed level because of noises consequent to irregular reflection or the like from a near obstacle 25, the threshold value variable means 30 changes the threshold value corresponding to the detected energy, so that detection of wrong information on the object resulting from the scan angle or noises can be prevented.